The invention relates to a semiconductor assembly including a power semiconductor assembly.
Power semiconductor assemblies of this type typically include one or more semiconductor chips mounted on a common carrier. In general, each of the semiconductor chips has two main connections which, in particular in the case of vertical components, are arranged on mutually opposite sides of the semiconductor chip.
It is customary for the individual chips to be electrically conductively mounted in each case on a carrier that simultaneously forms a connection of the component.
In general, power semiconductor assemblies of this type are used for switching a load. For this purpose, one of the main connections is electrically conductively connected to the load and the other of the main connections is electrically conductively connected to a supply voltage, one of the connections being formed by the carrier.
Such power semiconductor assemblies are often thermally contact-connected to a heat sink opposite the semiconductor chips in order to dissipate the heat loss arising in the semiconductor chips. Instead of the heat sink or in addition to the latter, a metal plate, a heat accumulator or a metallic film can be arranged on that side of the carrier which is remote from the semiconductor chips.
Coupling capacitances are formed here at any rate between those main connections of the semiconductor chips which face the carrier and a metallization of the carrier that is electrically conductively connected thereto, on the one hand, and the heat sink and/or the heat accumulator and/or the metal plate and/or the metallic film, which coupling capacitances lead to circuit losses particularly at high switching frequencies. If the heat sink, the heat accumulator, the metal plate or the metallic film is grounded, then the circuit losses essentially result from displacement currents in the ground conductor, and without grounding essentially from the emission of electromagnetic waves.